Queen's Pawn Game: Accelerated London System

The Accelerated London System (1.d4 d5 2.Bf4) brings White's dark-squared bishop out on move two, before the king's knight. It has become a common move order for the London System, a set-up White can play against almost any defence.

Origins

James Mason was the first master to play the London System regularly, including at Vienna 1882. The name comes from the London tournament of 1922, where it appeared seven times, in games by Capablanca, Alekhine and Rubinstein among others. It stayed rare at grandmaster level, but players such as Gata Kamsky, Levon Aronian and Magnus Carlsen have used it often, and in the 21st century it has become very popular at club level. Ding Liren won with it against Ian Nepomniachtchi in the sixth game of the 2023 World Championship.

Playing Bf4 on move two became common after Sverre Johnsen and Vlatko Kovačević's influential 2005 book Win with the London System. The point is to avoid the line 2.Nf3 Nf6 3.Bf4 c5 4.e3 Nc6 5.c3 Qb6 6.Qb3 c4 7.Qc2 Bf5, which Kiril Georgiev notes forces White's queen back to c1.

The idea

White builds the same structure whatever Black does: d4, Bf4, e3, Bd3, Nf3, Nbd2 and c3, often with h3 so the bishop can drop back to h2 and stay on the h2–b8 diagonal. The game is usually closed, and White often plants a knight on e5. Black's most common plan against the system is ...c5 and ...Qb6, hitting the b2-pawn once the bishop has left c1.

Main lines

• After 2...Nf6, White's usual e3, Nf3 and Nbd2 reach the standard London position.
• With Nc3 instead of c3 the game becomes the Rapport-Jobava System.
• With c4 instead of c3 White can transpose to the Queen's Gambit; Black can transpose to a Caro-Kann structure with ...c5 and ...cxd4 exd4.
• Black's set-ups include a Queen's Gambit Declined type with ...e6, ...c5 and ...Nc6, a symmetrical one with ...Bf5, and King's Indian or Queen's Indian set-ups.

Strengths and weaknesses

Strengths

• One set-up against nearly everything, with a smaller body of theory than most openings.
• Solid, with clear plans.

Weaknesses

• It has been criticised for leading to repetitive games and a lack of dynamic play.
• After Bf4 the b2-pawn is undefended, which ...c5 and ...Qb6 exploit.

Who should play it

The Accelerated London suits players who want a solid repertoire with 1.d4 built on one set-up; its solid nature and clear plans are why it has become so popular at club level.

The numbers

On Lichess White leads at every level: 52.8% against 43.2% under 1400, 51.5% against 44.1% at 1400–1799, 50.3% against 44.1% at 1800–2199 and 48.8% against 43.1% from 2200 up. In about 7,100 master games 44.9% were drawn; White won 31.3% and Black 23.8%.